[PATCH v2] Make PE images deterministic by default.
Cory Fields
cory@coryfields.com
Thu Nov 21 16:19:00 GMT 2013
Use --insert-timestamp to restore previous behavior.
binutils/Changelog
2013-11-21 Cory Fields <cory@coryfields.com>
* bfd/libcoff-in.h: Add insert_timestamp flag to the pe_data struct.
* bfd/libcoff.h: Update after change to bfd/libcoff-in.h.
* bfd/peXXigen.c (_bfd_XXi_only_swap_filehdr_out): Only use a real
timestamp if --insert-timestamp was used.
* ld/pe-dll.c (fill_edata): Likewise.
* ld/emultempl/pe.em: Add the --insert-timestamp option.
* ld/emultempl/pep.em: Likewise for 64bit.
* ld/ld.texinfo: Document the --insert-timestamp option.
---
bfd/libcoff-in.h | 1 +
bfd/libcoff.h | 1 +
bfd/peXXigen.c | 5 ++++-
binutils/ChangeLog | 10 ++++++++++
ld/emultempl/pe.em | 12 +++++++++++-
ld/emultempl/pep.em | 11 ++++++++++-
ld/ld.texinfo | 6 ++++++
ld/pe-dll.c | 7 +++----
8 files changed, 46 insertions(+), 7 deletions(-)
diff --git a/bfd/libcoff-in.h b/bfd/libcoff-in.h
index 6efbc52..17617d6 100644
--- a/bfd/libcoff-in.h
+++ b/bfd/libcoff-in.h
@@ -118,6 +118,7 @@ typedef struct pe_tdata
int dll;
int has_reloc_section;
int dont_strip_reloc;
+ bfd_boolean insert_timestamp;
bfd_boolean (*in_reloc_p) (bfd *, reloc_howto_type *);
flagword real_flags;
} pe_data_type;
diff --git a/bfd/libcoff.h b/bfd/libcoff.h
index 6270bab..d0959a9 100644
--- a/bfd/libcoff.h
+++ b/bfd/libcoff.h
@@ -122,6 +122,7 @@ typedef struct pe_tdata
int dll;
int has_reloc_section;
int dont_strip_reloc;
+ bfd_boolean insert_timestamp;
bfd_boolean (*in_reloc_p) (bfd *, reloc_howto_type *);
flagword real_flags;
} pe_data_type;
diff --git a/bfd/peXXigen.c b/bfd/peXXigen.c
index d0f7a96..9843825 100644
--- a/bfd/peXXigen.c
+++ b/bfd/peXXigen.c
@@ -793,7 +793,10 @@ _bfd_XXi_only_swap_filehdr_out (bfd * abfd, void * in, void * out)
H_PUT_16 (abfd, filehdr_in->f_magic, filehdr_out->f_magic);
H_PUT_16 (abfd, filehdr_in->f_nscns, filehdr_out->f_nscns);
- H_PUT_32 (abfd, time (0), filehdr_out->f_timdat);
+ /* Only use a real timestamp if the option was chosen */
+ if ((pe_data (abfd)->insert_timestamp))
+ H_PUT_32 (abfd, time(0), filehdr_out->f_timdat);
+
PUT_FILEHDR_SYMPTR (abfd, filehdr_in->f_symptr,
filehdr_out->f_symptr);
H_PUT_32 (abfd, filehdr_in->f_nsyms, filehdr_out->f_nsyms);
diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index cc9c6f9..24e4c61 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,13 @@
+2013-11-21 Cory Fields <cory@coryfields.com>
+ * bfd/libcoff-in.h: Add insert_timestamp flag to the pe_data struct.
+ * bfd/libcoff.h: Update after change to bfd/libcoff-in.h.
+ * bfd/peXXigen.c (_bfd_XXi_only_swap_filehdr_out): Only use a real
+ timestamp if --insert-timestamp was used.
+ * ld/pe-dll.c (fill_edata): Likewise.
+ * ld/emultempl/pe.em: Add the --insert-timestamp option.
+ * ld/emultempl/pep.em: Likewise for 64bit.
+ * ld/ld.texinfo: Document the --insert-timestamp option.
+
2013-11-13 Martin Mitas <mity@morous.org>
* rescoff.c (write_coff_file): Use 64-bit alignment for resource
diff --git a/ld/emultempl/pe.em b/ld/emultempl/pe.em
index 4df7753..bb25e53 100644
--- a/ld/emultempl/pe.em
+++ b/ld/emultempl/pe.em
@@ -130,6 +130,7 @@ static int support_old_code = 0;
static char * thumb_entry_symbol = NULL;
static lang_assignment_statement_type *image_base_statement = 0;
static unsigned short pe_dll_characteristics = 0;
+static bfd_boolean insert_timestamp = FALSE;
#ifdef DLL_SUPPORT
static int pe_enable_stdcall_fixup = -1; /* 0=disable 1=enable. */
@@ -259,8 +260,10 @@ fragment <<EOF
(OPTION_LEADING_UNDERSCORE + 1)
#define OPTION_DISABLE_LONG_SECTION_NAMES \
(OPTION_ENABLE_LONG_SECTION_NAMES + 1)
+#define OPTION_INSERT_TIMESTAMP \
+ (OPTION_DISABLE_LONG_SECTION_NAMES + 1)
/* DLLCharacteristics flags */
-#define OPTION_DYNAMIC_BASE (OPTION_DISABLE_LONG_SECTION_NAMES + 1)
+#define OPTION_DYNAMIC_BASE (OPTION_INSERT_TIMESTAMP + 1)
#define OPTION_FORCE_INTEGRITY (OPTION_DYNAMIC_BASE + 1)
#define OPTION_NX_COMPAT (OPTION_FORCE_INTEGRITY + 1)
#define OPTION_NO_ISOLATION (OPTION_NX_COMPAT + 1)
@@ -301,6 +304,7 @@ gld${EMULATION_NAME}_add_options
OPTION_USE_NUL_PREFIXED_IMPORT_TABLES},
{"no-leading-underscore", no_argument, NULL, OPTION_NO_LEADING_UNDERSCORE},
{"leading-underscore", no_argument, NULL, OPTION_LEADING_UNDERSCORE},
+ {"insert-timestamp", no_argument, NULL, OPTION_INSERT_TIMESTAMP},
#ifdef DLL_SUPPORT
/* getopt allows abbreviations, so we do this to stop it
from treating -o as an abbreviation for this option. */
@@ -438,6 +442,8 @@ gld_${EMULATION_NAME}_list_options (FILE *file)
fprintf (file, _(" --support-old-code Support interworking with old code\n"));
fprintf (file, _(" --[no-]leading-underscore Set explicit symbol underscore prefix mode\n"));
fprintf (file, _(" --thumb-entry=<symbol> Set the entry point to be Thumb <symbol>\n"));
+ fprintf (file, _(" --insert-timestamp Use a real timestamp rather than zero.\n"));
+ fprintf (file, _(" This makes binaries non-deterministic\n"));
#ifdef DLL_SUPPORT
fprintf (file, _(" --add-stdcall-alias Export symbols with and without @nn\n"));
fprintf (file, _(" --disable-stdcall-fixup Don't link _sym to _sym@nn\n"));
@@ -754,6 +760,9 @@ gld${EMULATION_NAME}_handle_option (int optc)
case OPTION_LEADING_UNDERSCORE:
pe_leading_underscore = 1;
break;
+ case OPTION_INSERT_TIMESTAMP:
+ insert_timestamp = TRUE;
+ break;
#ifdef DLL_SUPPORT
case OPTION_OUT_DEF:
pe_out_def_filename = xstrdup (optarg);
@@ -1255,6 +1264,7 @@ gld_${EMULATION_NAME}_after_open (void)
pe_data (link_info.output_bfd)->pe_opthdr = pe;
pe_data (link_info.output_bfd)->dll = init[DLLOFF].value;
pe_data (link_info.output_bfd)->real_flags |= real_flags;
+ pe_data (link_info.output_bfd)->insert_timestamp = insert_timestamp;
/* At this point we must decide whether to use long section names
in the output or not. If the user hasn't explicitly specified
diff --git a/ld/emultempl/pep.em b/ld/emultempl/pep.em
index 3e8b65e..c6cb626 100644
--- a/ld/emultempl/pep.em
+++ b/ld/emultempl/pep.em
@@ -146,6 +146,7 @@ static flagword real_flags = IMAGE_FILE_LARGE_ADDRESS_AWARE;
static int support_old_code = 0;
static lang_assignment_statement_type *image_base_statement = 0;
static unsigned short pe_dll_characteristics = 0;
+static bfd_boolean insert_timestamp = FALSE;
#ifdef DLL_SUPPORT
static int pep_enable_stdcall_fixup = 1; /* 0=disable 1=enable (default). */
@@ -241,7 +242,8 @@ enum options
OPTION_NO_SEH,
OPTION_NO_BIND,
OPTION_WDM_DRIVER,
- OPTION_TERMINAL_SERVER_AWARE
+ OPTION_TERMINAL_SERVER_AWARE,
+ OPTION_INSERT_TIMESTAMP,
};
static void
@@ -316,6 +318,7 @@ gld${EMULATION_NAME}_add_options
{"no-bind", no_argument, NULL, OPTION_NO_BIND},
{"wdmdriver", no_argument, NULL, OPTION_WDM_DRIVER},
{"tsaware", no_argument, NULL, OPTION_TERMINAL_SERVER_AWARE},
+ {"insert-timestamp", no_argument, NULL, OPTION_INSERT_TIMESTAMP},
{NULL, no_argument, NULL, 0}
};
@@ -402,6 +405,8 @@ gld_${EMULATION_NAME}_list_options (FILE *file)
fprintf (file, _(" --subsystem <name>[:<version>] Set required OS subsystem [& version]\n"));
fprintf (file, _(" --support-old-code Support interworking with old code\n"));
fprintf (file, _(" --[no-]leading-underscore Set explicit symbol underscore prefix mode\n"));
+ fprintf (file, _(" --insert-timestamp Use a real timestamp rather than zero.\n"));
+ fprintf (file, _(" This makes binaries non-deterministic\n"));
#ifdef DLL_SUPPORT
fprintf (file, _(" --add-stdcall-alias Export symbols with and without @nn\n"));
fprintf (file, _(" --disable-stdcall-fixup Don't link _sym to _sym@nn\n"));
@@ -707,6 +712,9 @@ gld${EMULATION_NAME}_handle_option (int optc)
case OPTION_LEADING_UNDERSCORE:
pep_leading_underscore = 1;
break;
+ case OPTION_INSERT_TIMESTAMP:
+ insert_timestamp = TRUE;
+ break;
#ifdef DLL_SUPPORT
case OPTION_OUT_DEF:
pep_out_def_filename = xstrdup (optarg);
@@ -1219,6 +1227,7 @@ gld_${EMULATION_NAME}_after_open (void)
pe_data (link_info.output_bfd)->pe_opthdr = pep;
pe_data (link_info.output_bfd)->dll = init[DLLOFF].value;
pe_data (link_info.output_bfd)->real_flags |= real_flags;
+ pe_data (link_info.output_bfd)->insert_timestamp = insert_timestamp;
/* At this point we must decide whether to use long section names
in the output or not. If the user hasn't explicitly specified
diff --git a/ld/ld.texinfo b/ld/ld.texinfo
index e4788f6..04325c6 100644
--- a/ld/ld.texinfo
+++ b/ld/ld.texinfo
@@ -2657,6 +2657,12 @@ The driver uses the MS Windows Driver Model.
@item --tsaware
The image is Terminal Server aware.
+@kindex --insert-timestamp
+@item --insert-timestamp
+Insert a real timestamp into the image, rather than the default value of zero.
+This will result in a slightly different results with each invocation, which
+could be helpful for distributing unique images.
+
@end table
@c man end
diff --git a/ld/pe-dll.c b/ld/pe-dll.c
index 7d5f90d..f3bf29c 100644
--- a/ld/pe-dll.c
+++ b/ld/pe-dll.c
@@ -1169,9 +1169,6 @@ fill_edata (bfd *abfd, struct bfd_link_info *info ATTRIBUTE_UNUSED)
unsigned char *enameptrs;
unsigned char *eordinals;
char *enamestr;
- time_t now;
-
- time (&now);
edata_d = xmalloc (edata_sz);
@@ -1186,7 +1183,9 @@ fill_edata (bfd *abfd, struct bfd_link_info *info ATTRIBUTE_UNUSED)
+ edata_s->output_section->vma - image_base)
memset (edata_d, 0, edata_sz);
- bfd_put_32 (abfd, now, edata_d + 4);
+ if (pe_data (abfd)->insert_timestamp)
+ H_PUT_32 (abfd, time(0), edata_d + 4);
+
if (pe_def_file->version_major != -1)
{
bfd_put_16 (abfd, pe_def_file->version_major, edata_d + 8);
--
1.8.1.2
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